The broad goal of this program of research is develop prevention/intervention program(s) that are (a) applicable under non-research conditions, (b) effective at reducing co-occurring internalizing and externalizing problems among pre-adolescent children, and (c) able to prevent these problems from becoming more serious. The proposed project focuses on the RECAP program, a school-based program for treating children's co-occurring internalizing and externalizing problems. The specific aims of the proposed project are to: (1) develop a client assignment model for different intensities of the RECAP treatment program, which requires (Step 1) identification of moderators of treatment response (i.e., identification of predictors of differential treatment response), and (Step 2) development of a Stepped Care assignment algorithm. If the proposed study is successful in identifying predictors of differential treatment response, a future study will implement Step 3 of the development process, which is to test whether the Stepped Care assignment algorithm is associated with better outcomes than random assignment. Specific Aims for the current proposed project also include (2) determining change processes underlying RECAP's treatment effects, and (3) conducting a second outcome study to confirm the results of a previous study indicating that RECAP is efficacious. Project participants will be 340 children and their families from four elementary schools serving low income neighborhoods, with participating children experiencing elevated levels of internalizing and externalizing problems. Participants will be assigned to one of four treatment variants varying in the intensity of treatment services: (a) a no treatment control group; (b) a treatment variant based on the RECAP teacher classroom component; (c) a treatment variant including the teacher classroom component as well as a child component; (d) a treatment variant including both of the preceding components as well as a parent training component. The intervention will last one academic year, with four cohorts of participants. Assessments will occur at four time points on symptoms, adaptive functioning, and hypothesized moderators and mediators of RECAP's treatment effects.